With the deepening of the information revolution,data has become a basic strategic resource for the country.At the same time,data security goes beyond traditional security and rises to the height of safeguarding national sovereignty.As one of the important technologies for maintaining data security,digital signatures can solve security problems such as forgery,repudiation,impersonation and tampering.Identity-based signature uses the unique identity information of the user as the public key,which efficiently solves the key management problem in traditional signature.Proxy re-signature can transform the signature,and strong designated verifier signature can protect the signer's identity privacy.To meet the security requirements brought by the new application environment,we carried out design and analysis research based on identity-based signature,proxy re-signature and strong designated verifier signature to solve some data security problems in an open and converged network environment.(1)Analyze the security of an efficient identity-based signature scheme.Huang et al.proposed an efficient identity-based signature scheme,and used the hybrid game approach to prove that their scheme was strongly unforgeable in the standard model and its security was dependent on the computational Diffie-Hellman(CDH)assumption.The analysis found that there are serious security defects in the security proof of this scheme,and gave specific attack methods.The attacker can distinguish the probability distribution between the simulated signature and the real signature with a non-negligible probability,and the challenger cannot use the forged signature of the attacker to solve the CDH problem.(2)Design a secure identity-based blind proxy re-signature scheme in the standard model.This scheme combines the advantages of identity-based signature and blind proxy re-signature.It not only has the function of signature conversion,but also can protect the privacy of the signed data.In the standard model,it is proved that this scheme is existentially unforgeable under the adaptive chosen message attacks.Performance analysis results show that this scheme is superior to the existing identity-based blind proxy re-signature schemes in terms of signature length and computational overhead.(3)Design a strong designated verifier proxy re-signing scheme for IoT envi-onment.In order to ensure the integrity of IoT data and protect the signer's identity privacy,the concept of strong designated verifier proxy re-signature is introduced,its formal definition and security model are given,and a concrete implementation scheme is constructed.This scheme is bidirectional,multi-use and non-transitive,and its security is proved in the standard model.The analysis results show that this scheme can not only protect the privacy of the signer's identity,but also provide non-delegatability for signature verification.In addition,based on this scheme,an example of environmental monitoring applied to the Internet of things is given. |